The working voltage of each solar cell (or photovoltaic cell, PV cell) is about 0.4-0.5V (open circuit voltage is about 0.6V). After cutting a piece of solar cell into two pieces, the voltage of each piece of solar cell is unchanged; the power of solar cell and the area of ​​solar cell will be proportional (in the case of the same conversion rate). According to the required voltage and power of the custom solar module, the area of ​​the required cell sheet and the number of cells can be calculated. Since the size of the cell (before cutting) is constant (there are several standards), the area usually cannot meet the needs of the solar module. Therefore, before welding, there is generally a process of laser dicing. Before cutting, the cutting route should be designed and sketched. The remaining solar cells should be cut as much as possible to improve the utilization of solar cells.
 
Specific requirements for slicing:
 
1. When slicing, the depth of the cut is generally controlled to 1/2-2/3 of the thickness of the solar cell, which is mainly controlled by adjusting the operating current of the laser dicing machine. If the working current is too large, the power output is large, and the laser beam is strong, the solar cell can be directly cut off, which is likely to cause a short circuit between the positive and negative terminals of the solar cell. Conversely, when the operating current is too small and the scratch depth is insufficient, it is easy to break the solar cell sheet when the solar cell is broken by hand along the scratch.
 
2, The solar cell is more expensive. In order to reduce the loss of the cell during cutting, before the formal cutting, the chopped cell with the same model as the cell to be cut should be tested to test the cell. The laser dicing machine has a suitable working current I0, so that the dicing machine in the cutting of the normal sample operates according to the current I0, which can reduce the loss due to the working current being too large or too small.
 
3. The laser dicing machine laser beam routing is determined by setting the XY coordinates of the computer. When setting the coordinates, an error in the decimal point and the coordinate axis will change the laser beam path. Therefore, before the solar cell is cut, use small The working current (so that the laser can be seen clearly) allows the laser beam to travel along the route of the temple. After confirming that the route is correct, adjust the current to slice.
 
4. Generally speaking, the laser dicing machine can only cut along the XY axis direction, and it is convenient to cut the square solar cell. When the solar cell piece is cut into a shape such as a triangle, the angle must be calculated before cutting, and the solar cell orientation is set so that the line to be cut is in the X or Y direction.
 
5. When cutting different solar cell pieces, if the thickness difference is large twice, adjust the working current and pay attention to adjust the focal length.
 
6. When cutting the solar cell, the vacuum pump should be turned on to make the solar cell piece close to the working panel. Otherwise, the cutting will be uneven.
 
Author: Carrie Wong
From WSL Solar Co., Ltd.
 
WSL Solar has been a quality and professional manufacturer of custom solar panels (or custom PV modules) and solar solution provider in China since 2006. With our in-house R&D team and management team for over 10 years' experience in solar industry, we are able to design and develop a customized solar module in a variety of sizes, shapes and outputs to meet our client's specific requirement, and provide solution support start from initial product development stage. For more detail, please visit https://www.wsl-solar.com/